Nickname for an uncle

So my son is 10 months old and we basically just refer to all his other uncles by “uncle + their name” but I have yet to come up with something for him to refer to my BIL because I feel weird calling him Uncle Sam and I feel like uncle Samuel is just a mouthful plus none of us call him Samuel. His middle name is Clinton and “uncle Clint/Clinton” just also feels like a mouthful and unnatural since we don’t ever refer to him by his middle name either. He hates “uncle Sammy” so that’s out too and I’ve got nothing. Please help